Scientech Vector - Manual (Page 5)

5
RELATIVE SPECTRAL RESPONSE
20
30
40
50
60
70
80
90
100
0.1 1 10 100
WAVELENGTH [microns]
P
E
RCENT AB
S
O
R
P
TION
P and SP
HR-P
PHD, PHDX*
and SPHD
HR-PHF
PHF and SPHF
*HDX Limited to 0.4 to 2.0 microns
PHDXUV
Figure 2
Before using your Vector pyroelectric detector, please review the energy density formulas given in the chart at
the front of this manual. Familiarize yourself with all of the specifications of the detector models which you are
using. A damage test slide is provided with each P and PHF type detectors, but not with PHD type detectors.
Fire the beam at the test slide before using the detector to be sure you are operating under safe conditions.
C
ORRECTING
P
YROELECTRIC
D
ETECTOR
O
PERATING
P
ARAMETERS FOR
U
SE
AT
D
IFFERENT
W
AVELENGTHS
:
NOTE: Due to variability in the manufacturing process the absorption characteristics of the HD and P
model detectors can vary in the UV region (190 to 400nm). Scientech recommends optical
calibration at 266nm if the detector is to be used in the UV region instead of relying on an
absorption rate in the chart at the end of this manual.
All pyroelectric detectors are calibrated at a specific wavelength and the detector’s output sensitivity is derived
for that wavelength. The output sensitivity and calibration wavelength is recorded in the Operating Parameters
section at the front of the manual and on the detector’s serial tag. When a pyroelectric detector is used at a
wavelength other than the calibration wavelength, its output sensitivity can be adjusted to compensate for the
absorption rate at the new wavelength. The new output sensitivity is calculated as follows:
1.
Find the absorption rate from the chart at the end of this manual for the calibration wavelength of your
pyroelectric detector.
2. Find the absorption rate for the wavelength where you will be working.
3. Determine the new output sensitivity using the following formula:
absorption rate of new wavelength x output sensitivity (V/J) = output sensitivity for new
absorption rate of the calibration wavelength wavelength from serial tag
D
ETECTOR
O
PERATION
W
ITHOUT AN
I
NDICATOR
:
Pyroelectric detectors can be operated with a 1MΩ input oscilloscope. The peak voltage shown on the
oscilloscope can be divided by the V/J output sensitivity of the detector to calculate energy.